Dynamo.



PATENTED APR. 11, 1905.

E. B. JAGOBSON.

DYNAMO.

APPLICATION FILED JAN. 27, 1904.

2 SHEETS-SHEET 1.

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(emf/ w M No. 787,184. PATENTED APR. 11, 1905.

E. B. JAGOBSONi DYNAMG.

APPLICATION FILED JAN. 27, 190.

2 SHEETS-SHEET 2.

UNITED STATES Patented April 11, 1905.

PATENT OEEIcE.

EDWARD B. JACOBSON, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO PITTSFIELD SPARK COIL COMPANY, OF PITTSFIELD, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

DYNAMO- SPECIFICATION forming part of Letters Patent No. 787,184, dated April 11, 1905.

Application filed January 27,1904. Serial No. 190,813.

To all whom it nuty concern:

Be it known that I, EDWARD B. JAooBsoN, a citizen of the United States, residing at Pittsfield, in the county of Berkshire, State of Massachusetts, have invented a certain new and useful Improvement in Dynamos, of which the following is a specification, reference being had therein to the accompanying drawings.

[0 The aim in general is to produce a dynamo of high efiiciency, light weight, and slow speed suitable for employment for the generation of electricity to be utilized in the production of sparks to ignite charges of explosive fuel in vapor orrgas engines.

Various special aims or objects of different features of the invention are indicated in the course of the following description.

I have shown in the accompanying drawings the invention in the best form of embodiment which I have thus far devised.

In the drawings, Figure 1 shows in plan a dynamo embodying the invention, portions of the casing being removed in order to show 2 5 the internal construction. Fig. 2 is a view in elevation, on a reduced scale, looking from the driving end, with the shaft 7 in section and the head end of the casing removed. Fig. 3 is a view in elevationfrom the left-hand 3 end in Fig. 1, with the cap removed and with the boss or projecting portion of the web of the intermediate section of the casing also removed. Fig. 4 is a view in section along the line A at of Fig. 3, showing the details of the form of brush mechanism which is represented in elevation in Fig. 3.

The casing in general of the dynamo is designated 1. The said casing is cylindrical in shape and preferably is constituted of several 4 sections which are united to one another. Preferably the said sections are formed with matching screw-threaded portions, and thereby united. The sections in the present instance comprise the main or body section 1,

the driving end head or end section 1 the intermediate or brush section 1, and the cap or head 1. For the convenient support of the dynamo the main or body section 1" is furnished in the present instance with a foot or pedestal 2, the latter serving as a means of 5 enabling the dynamo to be mounted upon a suitable base or support. The magnetic-field devices and the armature are inclosed by the said main or body section 1. As thus con structed the casing constitutes a dust-proof 5 5 inclosure for the various essential parts, the said inclosure being neat and compact and also easy to open and to take apart as well as put together again. The construction, moreover, is such as to enable the various contained parts to be applied or removed conveniently and readily.

The opposite poles of the field are designated 3 3, (see Figs. 1 and 2,) they. being inclicated in dotted lines in Fig. 2 and their polepieces being designatec 3 3 in Fig. 2. The said poles 3 3 are joined with each other by semicircular yokes 3 3". The coils which are applied to the said poles 3 3 are designated 4 4. The said coils are represented as wrapped in tape in customary manner. The armature is shown at 5 and its commutator as at 6, the shaft carrying the said armature and commutator being designated 7 and being mounted in bearings at 8 8, which are provided in the driving end section or head 1" and the intermediate or brush section 1, respectively.

At 7 is a pulley on the armature-shaft 7, by means of which the latter may be rotated in practice. The bearings at 8 8 preferably are ball-bearings. As will appear later from the specific description, the field is in a shuntcircuit.

One especial object of the invention is to render unnecessary the employment of a battery to excite the field in starting the engine.

To this end the yokes 3 3", which I employ, are permanent magnets. Thereby on rotating the armature at slow speed suflicient cur- 9o rent is enabled to be produced to form sparks, whereby the engine, in connection with which the dynamo is employed, may be started.

In order to avoid any loss of the magnetic lines of force which are created by the fieldcoils becoming energized, each pole 3 is ing would be fully operative.

body or main section 1*of the casing. The casgrooved at its outer end to receive the end portions of the yokes 3 3", as shown best in Fig. 1, in which figure will be seen the partitions or ribs 3 3, which are left by the grooving. The result of this is an increased magnetic surface for the magnet-yokes 3 3 For the purpose of joining the parts and combining them into a compact organization the ends of the permanent magnet-yokes 3 3 are connected with the poles 3 3 by means of screws 3 3. The employment of the said connecting means tends to diminish any possible magnetic reluctance between the poles and the permanent magnet-yokes.

The organization constituting the magnetic field is practically complete in itself and even if used without a receiving and inclosing eas- The said organization in being combined with the casing simply is slipped bodily into the opening of the ing constitutes merely a container or support for the magnetic field and itself may be made of non-magnetic material such, for example, as aluminium. Sometimes in practice I employ aluminium as the material of which the casing is formed in order to secure greater lightness.

For the purpose of correctly positioning the magnetic field within the section 1 of the casing the said section is provided with a stud 61, Fig. 2, which projects inwardly from the inner surface of its shell, so that as the fieldpiece is slipped into the section 1 the proximate ends of the permanent magnet-yokes at the right-hand side in Fig. 1 assume positions on opposite sides of the said stud, as represented in Fig. 2. This compels the placing of the field-piece in correct position within the casing when assembling the parts and provides against accidental loss of position by rotary movement within the casing after the parts have been assembled. In order to protect the parts from the effect of jarring, such as will be experienced in the use of a dynamo embodying my invention upon a vehicle, for which use the said dynamo is largelyintended, the field organization is shaped exteriorly to correspond closely with the interior contour of the body or main section 1 of the casing, and the said organization fits snugly within the said section.

The brushes which cooperate with the commutator 6 are indicated at 8 8 in Figs. 1 and 3. The brushes and the means and manner of holding the same in contact with the commutator may be of any approved character and arrangement. I contemplate in practice employing the construction and arrangement which I have presented in my application for United States Letters Patent for improvement in brushes and brush-holders for dynamos filed August 20, 1903, Serial No. 170,167.

1 have presented the main features of the construction in the drawings hereof and will now refer briefly to the same.

The brushes 8 8 are contained in tubular cylindrical brush-holders 9 9 and are pressed against the surface of the commutator by means of spring-actuated presser-arms 11 11, which latter act to take up the wear of the brushes, as well as hold them with certainty in contact with the commutator. The presserarm 11, which cooperates with each brush 8, is supported by a pivotal stud 111 and is acted upon by a spring 112, the free extremity of which latter bears against a projection 113 on the outer side of the presser-arm, the said spring tending to move the presser-arm in a direction to force the corresponding brush radially inward against the periphery of the commutator. For the purpose of enabling the tension of the spring112 of each presserarm to be adjusted so as to vary as desired the force with which the brush is pushed into contact with the commutatora hub 114c is litted upon the corresponding stud 111 with capacity to turn thereon. The presser-arm 1 1 is sleeved upon the exterior of the said hub, so as to turn freely thereon. The hub 11 1 has upon its outer end a circular series of projections 116 and also a radial flange 115. The coil or spiral which forms a portion of the spring 112 encircles the hub between the said fiange and the arm 11, and the corresponding end of the spring is engaged with the hub. It will be perceived that the hub constitutes a support forthe coil portion of the spring, and it being held normally from rotation with the spring it forms an abutment from which the spring reacts in pressing against the projection 113 of the presser-arm 11. For the purpose of preventing the hub from turning under the action of the spring a pin 117 is passed transversely through a hole in the outer end of the stud 111, the opposite ends of the said pin projecting on opposite sides of the said stud and being adapted to enter between adjacent projections of the series of projections 116. The hub is chambered atits inner side to receive an expanding spiral spring 118. The said spring is compressed between the interior shoulder of the hub and the adjacent collar or washer 119 next the fixed support of the stud. It acts with a tendency to hold the said hub pressed outwardly on the stud with certain of the projections 116 in engagement with the pin 117. The said engagement of the pin 117 with the said projections of the hub prevents the hub from turning under the influence of the tension of the spring. If, however, it is desired to adjust the said tension, this may be accomplished by pressing the hub inwardly along the stud 111, so as to compress the spring 118 and far enough to disengage the projections 116 from the pin 117, and then turning the hub in either direction, as may be required in order to in- ITS crease or diminish the tension of the spring to the required degree, after which on relieving the lateral pressure against the hub and permitting the spring 118 to press the hub outwardly again the projections 116 of the hub will reengage with the pin 117, carried by the stud 111, and lock the hub in its position of adjustment. The free extremity of each presser-arm 11 works within vertical slots 91 91, which latter are formed through the upper and lower sides of the corresponding brushholder 9. By the walls of the said slots the presser-arm is held in proper position and guided in its movements.

In conformity with the invention the brushsection 1 of the casing is formed with a transverse web 10. (See Figs. 1 and 3.) The said Web constitutes the carrier or support for the brushes and is, in effect, an integral portion of the casing. The brush-holders and also the presser-arms are insulated from the web in manner which I will presently describe. In order to obviate necessity for causing the current to flow from the brush through the presser-arm itself and also through the spring 112, which actuates such arm, the stud 111, on which the presser-arm is mounted, is itself placed in direct electrical communication with the adjacent brush-holder through the medi um of a plate 12, to which the bruslrholder and the said stud are applied and with which they are in electrical contact. a The plate 12 itself is insulated from the web 10 by means of a sheet 121,0f vulcanized fiber or other suitable insulating material, the fastenin gs by which the parts are united together being suitably insulated from the web 10. The inner end of the stud 111 is extended through a transverse hole in the web 10, and this hole is bushed with insulating material. The said inner end of the stud is screw-threaded and receives a nut 13, which latter is insulated from the web by a suitable washer, as shown. Were the spring 112 included in the circuit, it would tend to become heated during the operation of the dynamo, and the result of the heating would be to destroy its temper, rendering it useless or ineflicient.

Referring now to the wiring, from the respective studs 111' 111 wires 14 14 extend within the brush-section 1 to and connecting with the binding-posts 15 15, which latter project from the exterior of the said section. To the said binding-posts in practice areconnected the main conducting-wires. With the posts 15 15 are connected also the outer extremities of the wires 16 16 pertaining to the sh unt-circuit, the said wires passing through metal bushes 17 17 .that are set in holes in the rim of the brushsection 1, to the interior of the said brushsection and then passing through holes 18 18 in the web 10 to the exterior of the latter and connected with the binding-posts 19 19. The holes 18 18 are bushed with insulating material, as shown, and the posts 19 19 are insulated from the web. The binding-posts 19 19 also are connected to the extremities of the wire 20 of the coils 1 4, such extremities extending from the said coils through holes 21 21 extending transversely through the Web 10 and bushed with insulating material, as shown. The metal bushes 17 17 are employed in order that there may be no leakage resulting from chafing of the insulating-covering of the wires 16 16 at the places where such wires pass through the shell of the brushsection 1. The said metal bushes are connected by metal strips 171 171 with the binding-posts 15 15.

\Vhile I have been particular to describe the invention in the best form of embodiment which I have thus far devised, it is of course evident that various modifications in construction, arrangement, 850., may be made within the spirit of my invention.

I claim as my invention 1. In a dynamo, in combination, the armature, the casing having a body or shell, and the field organization comprising, essentially, the poles, field-coils, and opposite segmental yokes joining the said poles togethefl the said field organization having exteriorly a sliding fit within the said body or shell, and adapted as a united whole to be inserted or removed by an endwise movement.

2. In a dynamo, in combination, the armature, the casing having a body or shell and provided with removable end sections having bearings for the journals of the said armature, and the field organization comprising, essentially, the poles, field-coils, and opposite segmental yokes joining the said poles together, the said field organization having exteriorly a sliding fit within the said body or shell, and adapted as a united whole to be inserted or removed by an endwise movement.

3. In a dynamo, in combination, the casing having acylindrical body or shell, and the field organization, cylindrical in exterior cross-section and comprising, essentially, the poles, the field-coils, and the opposite circular segmental yokes joining the said poles together, the said field organization having a sliding fit within the said body or shell, and adapted as a united whole to be inserted or removed by an endwise movement.

4. The combination with an armature, and a field organization, of the main or body section of the casing, inclosing and supporting the field organization, the head end section and brush-section removably applied to the opposite ends of the said main or body section and provided with bearings for the armature, the brushes carried by the said brush-section, and the end cap covering the brushes and exposing the latter by its removal.

5. The combination with an armature, and a field organization, of the main or body section of the casing, inclosing and supporting the field organization, the head end section IIO removably applied to one end of the said main or body portion and provided with a bearing for the armature, the brush-section removably applied to the other end of the said main or body section and provided with a transverse web having a bearing for the armature, the brushes mounted upon the said web, and the end cap covering the brushes and exposing the latter by its removal.

6. The combination with the armature, the main or body section of the casing, the head end section and brush-section removably applied to the opposite ends of said main or body section and respectively provided with bearings for the armature the brushes applied to the said brush-section, and the end cap covering the brushes and exposing the latter by its removal, of the removable field organization having a sliding fit within the said main or body portion of the casing and comprising, essentially, the poles, the segmental yokes joining the poles, and the field-coils.

7. The combination with the rotating armature, the poles grooved transversely at their outer ends, and the lield-coils surrounding the said poles, of the opposite segmental yokes consisting of strips located side by side and having the ends thereof seated in the grooves of the respective poles and between the raised partitions produced by the grooving.

8. The combination with the rotating armature, the poles grooved transversely at their outer ends, and the lield-coils surrounding the said poles, of the opposite segmental yokes consisting of strips located side by side and having the ends thereof seated in the grooves of the respective poles and between the raised partitions produced by the grooving, and the screws securing the said ends to the poles.

In testimony whereof I aliix my signature in presence of two witnesses.

EDWARD B. JACOBSON.

lVitnesses:

Emmnp T. SCULLY, Jos n m i M. M cMA lion. 

